918 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [12] © 
known. The oyster and the mussel are also among the mollusks raised 
at Giens. This marine establishment has been founded on the banks of 
a concession, measuring not less than 10 hectares (25 acres). The shores 
slope gently, and the sea-weed, with which they are almost everywhere 
covered, converts them, as it were, into marine meadows, similar to the 
‘Serassats” of Arcachon, which are known at Toulon by the name of 
“mates.” The soil is formed of a mixture of clay, sand, and calcareous 
deposits. The proximity of aquatic plants for the raising of shell-fish and 
other fish offers undeniable advantages, particularly in the Mediterranean. 
In the ocean the breeding parks are, at times, almost entirely uncovered, 
and the tide furnishes them with well wrated water. The tide also 
brings to the shell-fish confined there abundant and fresh food from all 
directions. The case is different in the Mediterranean. At less than 
50 meters (160 feet) from the shore, except during storms, the bottom 
is never brought into contact with the outer air, and the animals which 
have not the power of locomotion are forced to feed on little else than 
what grows upon the bottom within a very restricted area. But in the 
present case aquatic plants tend to render less noticeable the effects 
resulting from the absence of tides. They always set free a small quan- 
tity of oxygen and produce multitudes of microscopic insects, which fur- 
nish food to other animals. These were not the only considerations 
which induced the Messrs. Gasquet to establish themselves on the pe- 
ninsula of Giens. The numerous kinds of shell-fish which took refuge 
in the gulf and the fine oysters occasionally found there were indications 
of the possibility of success. 
In connection with the experiments of acclimation which the Messrs. 
Gasquet have made on the shell-fish brought from Cette, experiments 
which have given the most favorable results, I have thought it would 
be interesting to make known the chemical composition of the waters of 
ethe breeding-parks. The following is an analysis made in the labora- 
tory of M. Schutzenberger, a professor in the College of France: 
Sodiam and! potassium 2.22 25230 Sch sk sec le Jee ee ee eee nee 1T02 
Chlorine andibromine)....225 2 seen ose mc ose oe ee ee eee 21.61 
Maonesiahsn S226 2 ce itecen loots scp. ccsbs o oboe weet eee ee eee 3.03 
Sulphuric Berd) n.) c Sak 2 occ bse: ck eisisiers see Siac oe Be ee bale 
40.78 
Residuum for 1 liter (about 1 quart—61 cubic inches) .......-..-..----.-------- 41. 23 
With some slight differences, the water at Cette resembles that at 
Giens. This fact must be borne in mind, for it shows that the acclima- 
tion of foreign species can only be obtained without difficulty, when the 
medium whence those species are taken closely resembles that in which 
they are to be placed. The water of the roadstead has a density of 3° 
by the hydrometer; its temperature is very variable; it attains, and even 
exceeds, 24°. This is not, however, an unfavorable condition. Under 
the action of the heat and the beneficial influence of the rain-water, the 
Shell-fish rapidly develop. 
